Folding leg system



Oct. 25, 1955 D. B. CHESKIN 2,721,628 I FOLDING LEG SYSTEM Filed Nov.23, 1954 Figure Figure 3 Bent Plate 5 WWWWWW A TTOR/VEY:

United States Patent FOLDING LEG SYSTEM David B. Cheskin, Chicago, Ill.Application November 23, 1954, Serial No. 470,703 3 Claims. (Cl.1878.49)

This invention relates to a folding leg arrangement for movableplatforms and the like and more particularly to a folding leg supportingsystem which will automatically fold or position a hinged supporting legconnecting to vertically movable platform means.

It is frequently desirable to have supporting leg means for lifts,elevators, platforms, etc. which are moved between different levels, asfor example, hydraulically raised loading platforms moving from abasement level to a street level, or from a street level to a car level.Such vertically movable platform means may have a plurality of legswhich fold under the platform, as it is lowered, and conversely, aconstruction which permits the leg means to unfold when the platform israised, with such leg means providing suitable vertical supports for theplatform while it is in use in its raised position. However, many typesof folding leg supporting means do not operate entirely automaticallyand require manual operations to fix them in the raised position, or mayat least require manual operations to initiate the folding action.

It is thus the principal object of the present invention to provide afolding leg construction which incorporates means to automaticallyeffect the folding of the leg means as the platform is made ready forlowering into its lowermost position, as well as means which will permitthe legs to come to bear on a suitable supporting seat.

Briefly, the present invention provides a folding leg supporting systemfor a movable platform means and the like, comprising in combination, aleg member having a top hinging means connecting it with a movableplatform means, a horizontal pin member connecting with the lower end ofthe leg member, a raised seat and guide section positioned below saidleg member, with the seat and guide section having a flat leg supportingupper surface and a downwardly sloping leg guiding section ex tendingfrom the edge of the supporting surface, a movable vertically positionedcurved plate pivotally connected to the seat section and positioned in amanner to lie across the flat leg supporting surface, the curved platebeing positioned in substantial vertical alignment below the horizontalpin at the lower end of the leg member and further having a downwardlysloping edge portion providing a nose-like projection extending beyondthe fiat surface of the raised seat section and a short distance overthe upper part of the downwardly sloping leg guiding section, wherebythe sloping edge portion of the curved vertically positioned plate mayengage the horizontal pin at the lower end of the leg member when thelatter is being lowered and effecting a sliding and folding of the legmeans as the latter subsequently follows the downwardly sloping legguiding section as the platform means is being lowered, and whereby alower edge surface of the projecting nose-like piece of the curved plateengages the horizontal pin member at the lower end of said leg memberwhen the platform is being raised causing the leg member to pivot andlift the curved plate member from the upper flat supporting surface ofthe seat and guide section and permit the lower 'end of the 2,721,628Fatented Oct. 25, 1955 leg member to rest vertically on said flatsupporting surface.

The actual construction of the folding leg supporting system and itsadvantages in actual operation will be better understood by reference tothe accompanying drawing and the following description thereof.

Figure 1 of the drawing shows, in elevational view, the folding legarrangement with the leg member in its vertical position resting on itslower seat and guide section.

Figure 2 of the drawing shows, in elevational view, the lower end of thefolding leg member raised slightly above the leg supporting and guidesection in the overrun position of the platform, (which is effected justprior to lowering the platform to a lower level).

Figure 3 of the drawing is also an elevational view of the lower end ofthe leg and the seat and guide section, as indicated by the line 33shown in Figure 2.

Figure 4 of the drawing illustrates the lower end of the folding legmember following the guide plate along its downwardly sloping surface sothat the leg member is ultimately folded under the lowered platform.

Figure 5 shows an alternate construction for the lower end of the hingedleg member.

Referring now to the drawing, there is shown in Figure 1, a folding legmember 1 pivotally connected by means of pin means 2, to the undersideof a vertically movable platform 3. The pin means 2 is shown asextending through a bracket 4, which in turn connects to an I-beammember 5 on the under side of the platform 3. However, other types ofpivot connections or hinged means may be utilized at the top of the legmember 1 to suitably pivotally connect the latter to the underside ofthe movable platform 3. The leg member 1, in this embodiment, is formedwith two spaced structural angle members which are tied together bysuitable spaced batten plates 6, while at the lower end is a bolt or pinmember 7 and an intermediate spacer 8 which acts as a horizontal contactpin for engaging and moving a pivotally movable vertically positionedrocking plate 9.

Directly below the leg supporting member 1, on a suitable base orfoundation, there is provided a leg supporting seat and guide section10. The section 10 has a downwardly sloping bent plate member 11extending from an upper leg supporting flat seating surface 12 to thebase or foundation surface whereby the pivotally hinged leg member maybe guided outwardly into a substantially horizontal folded position asthe platform is ultimately lowered to a lower level. As may be notedfrom both Figures 1 and 3, the seat and guide section 10 is formed inpart from a section of an I-beam structural member, while the bent platemember 11 is welded or otherwise connected to a cut out edge portion ofthe base 10. Connecting to the seat and guide section 10 are spaced pinsupporting plates 13, which in turn hold a bolt or pin member 14 thatpasses through one side of the pivotally movable rocking plate 9.

i The movable plate 9 has a special construction and arrangement whichis adapted to work with the horizontal pin member or spacer 8 at thelower end of the leg member 1 such that the latter is automaticallyguided to its proper position. In Figure 1, it will be noted that thecurved plate member 9 passes between the angle members of leg member'land is resting on the top of the spacer 3 while the leg member is inturn resting on the flat upper surface 12 of the seat and guide section10. This positioning is obtained automatically as the pivoting legmember 1 unfolds when the platform 3 is raised and the lower end of theleg member 1 is dragged along the guide plate 11 to ultimately have itslower end rest on the seating surface 12. In other words, the curvedplate member 9 is especially constructed to extend with a noselikeprojection A a short distance over the upper end of the plate 11 so thatit will be picked up by the spacer 8 on horizontal pin 7 and the plate 9rocked back into the position shown in Figure 1 of the drawing, pivotingabout the pin 14.

When it is desired to lower the platform 3 and effect the folding of theleg member 1, the platform is mechanically lifted, or otherwise raised,upwardly for a suitable short overrun, indicated in Figure 2 of thedrawing, such that the lower end of the leg member 1 rises free of theseat and guide section and above the vertically movable pivoted plate 9.Thus, the plate 9 automatically falls down into the position shown inFigure 2 and extends across the seating surface 12 and projects, withits nose-like portion A, a short distance over the bent plate 11. Itwill be noticed that plate 9' is also provided with a downwardly slopingor curved upper edge portion B which is utilized to contact the lowerside of the spacer S on pin 7 and effect the guiding and positioning ofthe lower end of the leg member 1 outwardly and over the projection Aand on to the sloping surface of bent plate 11. The latter guides theleg member still further outwardly and into a folded position as theplatform continues to lower. Although not necessary, it may be desirableto provide a small curve to the lower end of the leg member 1 such as Cwhich will cause the latter to ride more smoothly along the bent plate11 and effect its folding and unfolding without undue catching, orfrictional resistance. Figure 4 of the drawing shows the lower end ofthe leg member 1 moving along the surface of the curved bent plate 11.This figure also shows that the vertically movable pivoted plate 9 is inits lowered position resting across the seating surface 12 andprojecting outwardly a short distance over the upper end of the bentplate 11. Thus, when the raising of' the platform 3 is effected, it willbe seen that the lower end of the leg member 1, as it is allowed togradually straighten out and come into a substantially normal position,will have the lower pin 7 and spacer 8 engage the lower edge of thenose-like projection A of plate 9 and move or rock back the latter intothe position shown in Figure l of the drawing. The weight of the legmember 1 itself will permit the leg to assume its proper verticalposition for supporting purposes, with the very lower extremity of legmember 1 coming to rest on the upper seating surface 12 a short distanceaway from the upper end or edge of the plate member 11. counterweightmeans 16 may be added to one side of the leg member, such as to thebatten plates 6, so that the leg will come to a proper verticalposition. However, to assure that the leg member 1 comes into a verticalposition without swinging too far into an off-center position whichmight not provide adequate supporting means, a suitable stop member isprovided at the upper hinged end of the leg member 1. The stop member 15being attached to the under side of the connecting plate 4 andpositioned properly so that it engages one vertical edge of the legmember 1 to effect its proper vertical positioning.

In effecting the lowering of the platform 3 and the folding of the legmember 1, from the position shown in Figure 1- of the drawing, it is ofcourse necessary on each occasion to effect a slight lifting of theplatform and the leg member 1 as indicated by Figure 2, whereby, aspreviously described, the platform may then be lowered and the legmember 1 will pass over the edge of plate 9 and onto plate 11 to effectthe aforedescribed folding.

While the aforedescribed embodiment illustrates the leg member 1 asbeing formed of two structural angle members being spaced apart topermit the plate member 9 to pass therebetween at the lower edge andengage the spacer 8 on pin 7, it should, of course, be noted thatvarious modifications can be made in the design and arrangement of thelower end of the leg member 1. For example, where a single structuralangle member is used, or a channel member, or any other desired shape,then a horizontal pin member may project from merely one side of the legsupporting member and engage the seat and guide section and all of itsactuating portions in a manner similar to that set forth. In Figure 5 ofthe drawing, there is shown a leg member indicated as 1 that is of achannel construction with a pin such as 7 projecting from the back webportion of the channel member which is adapted to engage the movablerocking plate member 9. In this folding leg arrangement, a verticalalignment between the guide and seat section may be substantially asshown in the previously described arrangement, except that the verticalalignment between the plate member 9 and the back of the leg member 1must be such that the movable plate 9 will not contact the lower end ofthe leg member but will engage the horizontally projecting pin member 7Thus, the leg member can be guided for folding purposes in the samemanner as herein described in connection with the embodiment having thespaced angle member construction.

I claim as my invention:

1'. A folding leg supporting system for movable platform means and thelike, comprising in combination, a leg member having a top hinging meansconnecting with a vertically movable platform means, a horizontal pinmember through the lower end of said leg member, a raised seat and guidesection positioned below said leg member, said seat and guide sectionhaving a fiat leg supporting upper surface and a downwardly sloping legguiding portion extending from the edge thereof, a vertically movableand vertically positioned curved plate pivotally connected to said seatsection and positioned to move across said flat leg supporting surfacethereof, said curved plate being maintained in vertical alignment withthe horizontal pin portion of the lower end of said leg member wherebyto engage the latter, said vertically positioned curved plate furtherhaving a downwardly sloping edge portion providing a nose-likeprojection extending across said flat seating surface and a shortdistance over the upper part of the downward sloping portion of the seatand guide section, the sloping edge portion of said curved plate adaptedto engage said horizontal pin at the lower end of said leg member whenthe latter is being lowered and effecting a sliding and folding of theleg when said platform means is being lowered, and the lower surface ofsaid nose-like projection of said curved plate adapted to engage saidpin member at the lower end of said leg member whereby the latter liftsthe curved plate member vertically from the upper supporting surface ofthe seat, and guide section when said leg member is raised verticallyand allowed to rest on the supporting surface.

2. The folding leg supporting system of claim 1 further characterized inthat said top hinged leg member has a bifurcated lower end portion andsaid horizontal pin means extends through the spaced portions of thebifurcated leg member end, said vertically movable curved plate meansconnecting. to the seat and guide sections maintained in verticalalignment between said spaced portions of the bifurcated lower end ofsaid leg member and the interior portions of said horizontal pin memberthrough the bifurcated lower end of said leg member to contact saidcurved plate member between the spaced portions of the lower end of saidplate member.

3. A folding leg supporting system for a movable platform means and thelike, comprising in combination, a leg member having a top hinging meansconnecting it with a vertically movable platform means, a horizontal pinmember extending through the lower end of said leg member, a raised seatand guide section positioned below said leg member, said seat and guidesections having a fiat leg supporting upper surface and a downwardlysloping leg guiding plate extending from the edge of said upper surface,a vertically movable andvertically positioned curved plate memberpivotally connected to said seat section and maintained in a positionacross said fiat leg supporting surface of said seatsect-ion in verticalalignment under the horizontal. pinmember at the lower end of said leg;mem- 5 her, pivot means extending upwardly from said seat section andconnecting with said pivotally connected curved plate whereby the lattermay rock vertically upwardly and downwardly from pivot means, saidvertically positioned curved plate further having a downwardly slopingedge portion providing a nose-like projection extending across said fiatleg supporting surface and a short distance over the upper end of saiddownwardly sloping guide plate of said guide section, said sloping edgeportion of said curved plate adapted to engage said horizontal pin atthe lower end of said lift member to cause the latter to move outwardlyand over said bent downwardly sloping plate, said seat and guide sectionwhen said leg member holds with the lowering of said platform means, andthe lower surface of said nose-like projection of said curved plateadapted to engage said pin member at the lower end of said plate memberwhereby the latter Will lift said curved plate member vertically fromsaid upper leg supporting surface of the seat and guide section whensaid platform means is being raised and said leg member is raisedvertically and allowed to have its lower end rest 10 on said fiatsupporting surface.

No references cited.

